1. Field of the Invention
This invention is concerned with 2,2'-azobis-(4,5-imidazoledicarbonitrile), its alkyl derivatives, salts, metal complexes, hydrolysis products and hydrazine and hydroxylamine adducts.
2. Description of the Prior Art
A. Kreutzberger, J. Org. Chem. 27, 886-91 (1962); A. Kreutzberger and R. Schucker, Arch. Pharm. 305, 935-40 (1972); and A. Kreutzberger and R. Schucker, Arch. Pharm. 306, 139-45 (1973) show a group of 2,2'-azobisimidazoles having aryl or aliphatic substituents in the 4,5,4',5' positions. The compounds are red to violet in color.
H. Beyer et al., Chem. Ber. 101, 3151-62 (1968), prepared 2,2'-azobisimidazoles with 2-4 aryl substituents in the 4,5,4',5' positions by oxidizing the corresponding 2-aminoimidazoles with activated manganese dioxide.
A. F. Pozharskii et al., Khim. Geterotsikl. Soedin., 1970, 1267-72, prepared 2,2'-azobis(benzimidazole) by treating 1-benzyl-2-aminobenzimidazole with sodium in liquid ammonia.
M. Ruccia et al., Ann. Chim. (Rome), 50, 335-42 (1960), prepared aryl substituted 4,4'-azobisimidazoles) by nitrous acid coupling of the corresponding 4-amino and 4-unsubstituted imidazoles.
K. Hoffman "Imidazole and Its Derivatives", Interscience Publishers, Inc., N.Y. (1953), pgs. 136-141. In the Pauly test for the immidazole ring, the reaction of an imidazole and a diazonium salt in aqueous sodium carbonate yields the corresponding unsymmetrical phenyl-2-azoimidazole.
O. W. Webster, U.S. Pat. No. 3,770,764 discloses 2-substituted-4,5-dicyanoimidazoles. None of the prior art discloses the compounds of this invention.